The description of the MonitorWait event is:
Sent when a thread is about to wait on an object.
That is, a thread is entering Object.wait().
The second sentence is confusing because it is unclear if the thread has actually entered Object.wait() and more confusingly which of the "wait" methods on Object. Note that one wait method may call another.
Note that the MonitorWaited event description has a second sentence that is confusing in the same way.

Comments

EVALUATION
Should be fixed. See Suggested Fix. In a future release the spec should be appropriately clarified.